1. Explain grayscale input still read as three channel
2. Fix typo
3. Add more details to image match explanation to include the use of masks

AutoBuffer::allocate(nsz) didn't work properly when
(sz < nsz < fixed_size). In this case sz remained unchanged.

CMake doesn't work with empty paths ("") or paths which contains "./"

change the `while` loop to check if the two windows created by this example still exist, stop the program otherwise

removed binary

update

I could not find the cause of the error:

```
C:\builds_ocv\precommit_opencl\opencv\modules\ts\src\ts_perf.cpp(361):
error: The difference between expect_max and actual_max is
8445966.0000002384, which exceeds eps, where

expect_max evaluates to 0.9999997615814209,

actual_max evaluates to 8445967, and

eps evaluates to 1.0000000000000001e-005.

Argument "dst0" has unexpected maximal value
```

Hope this is a false alarm.

The three new functions:

```cpp
void cvStartWriteRawData_Base64(::CvFileStorage * fs, const char* name,
int len, const char* dt);
void cvWriteRawData_Base64(::CvFileStorage *
fs, const void* _data, int len);
void
cvEndWriteRawData_Base64(::CvFileStorage * fs);
```

Test is also updated. (And it's remarkable that there is a bug in
`cvWriteReadData`.)

CPack can't work with absolute paths.

opencv_ts is static internal library and in case of exporting
it requires all static dependencies (include HAL files)

Linker dependencies are transitive for non-private